U.S. Pat. No. 4,429,952, issued Feb. 7, 1984, describes a tracking reflector assembly for a skylight invented by the present inventor. The tracking reflector assembly disclosed therein is described in conjunction with a skylight, the reflector assembly automatically tracking daily and seasonal movements of the sun for increasing the amount of sunlight directed through the skylight. The tracking reflector assembly includes a ring-shaped base member rotatably supported above the skylight, as well as a reflector pivotally coupled to the ring-shaped base member. A horizontal drive motor engages the ring-shaped base member to horizontally rotate the reflector; a vertical drive motor secured to the rear face of the reflector operates in conjunction with a pair of rack arms for raising and lowering the reflector. Control circuitry, including various photosensors, is provided for selectively operating the horizontal and vertical drive motors. In addition, an apparatus is described for sensing the presence of dangerously high wind conditions to simulate the onset of darkness for closing the reflector to a lowered position.
U.S. Pat. No. 4,114,186, entitled "Lighting Fixture," and issued to the present applicant, discloses a solar lighting fixture, which, in one embodiment thereof includes a telescoping cylindrical light duct including a rotatable top portion having a pivotally connected reflective lid. Drive motors are also provided for rotating the top portion to follow movements of the sun, as well as to open and close the reflective lid.
Other U.S. patents which generally relate to apparatus for illuminating the interior of a building with solar light and/or reflecting solar light upon a solar energy collector include U.S. Pat. Nos. 668,404 (Hanneborg); 1,254,520 (Macduff); 3,709,583 (Pfannkuch et al.); 4,126,379 (Wu); 4,266,530 (Steadman); and 4,297,000 (Fries).
It is also known in the art to use solar energy for the purpose of generating electrical power, and various solar tracking mechanisms have been proposed for continuously positioning photocells to face the sun. For example, U.S. Pat. No. 4,225,781 (Hammons) discloses a solar tracking mechanism which is described for use in conjunction with various types of solar collectors, including a photovoltaic array. Also, in U.S. Pat. No. 4,295,621 (Siryj), a solar tracking mechanism is described for the purpose of orienting a device, such as a plurality of solar cells, to face the sun despite daily and seasonal movements thereof.
While tracking reflector assemblies for use in conjunction with skylights, of the type described in abovementioned U.S. Pat. No. 4,429,952, provide significant energy cost savings and improved daytime illumination of building interiors, energy savings are somewhat offset by the electrical power required to operate the horizontal and vertical drive motors thereof and the control circuitry related thereto. Moreover, installations of such tracking reflector assemblies upon the rooftops of building is sometimes hampered by the absence of an electrical power box upon the roofs of such buildings. In some cases, the building to be illuminated may be remote from conventional utility power lines.
Other problems may arise in attempting to power tracking reflector assemblies from utility power lines. Temporary electrical power outages result in such tracking reflector assemblies being unable to track movement of the sun, or being unable to open if closed prior to the power outage. Furthermore, power surges imposed upon utility power lines when electrical power is again turned on following such a power outage may damage the electrical components forming the circuitry used to control such tracking reflector assemblies. In addition, buildings having faulty grounding or other electrical wiring problems may allow voltage spikes to be coupled to the control circuitry for such tracking reflector assemblies, which voltage spikes may damage the components forming such control circuitry.
Photovoltaic panels are commercially available which are capable of generating the electrical power required to operate one or more tracking reflector assemblies of the type described above. However, such photovoltaic panels operate most efficiently only when they are generally facing the direction of the sun. While it is known in the art to provide a tracking apparatus for maintaining such photovoltaic panel directed at the sun, as evidenced by the above-referenced patents issued to Hammons and Siryj, the provision of such a complicated tracking mechanism in conjunction with such a photovoltaic panel would typically far outweigh the expense and inconvenience of simply extending the electrical power system of the building up to the rooftop thereof.
As mentioned above in regard to U.S. Pat. No. 4,429,952, it is known to provide an apparatus for sensing dangerously high wind conditions and to shade a photosensor in order to simulate darkness in response to such wind conditions. However, the wind detection apparatus disclosed within the '952 patent is of a type which, once activated by high winds, continuously shades a darkness photosensor until being manually reset by the user. Furthermore, the disclosed wind detection apparatus responds only to winds directed into the tracking reflector apparatus; while high winds emanating from other directions do not pose a threat to the structural integrity of the reflector assembly, such winds typically cause the reflector to vibrate which, in turn, has a distracting effect upon occupants of the building.
Accordingly, it is an object of the present invention to provide a tracking reflector assembly for use in conjunction with conventional skylights and which simultaneously generates sufficient electrical power to operate one or more of such tracking reflector assemblies and to generate electricity which may be used to power other electrical appliances within the building to be illuminated.
It is another object of the present invention to provide an apparatus which uniquely combines the advantages of a tracking skylight reflector assembly and a tracking photovoltaic panel into a single compact, efficient and economical structure.
It is a further object of the present invention to provide a tracking reflector assembly for a skylight and incorporating an improved wind detection apparatus responsive to high winds emanating from any direction while eliminating the need to manually reset such wind detection apparatus after high winds have subsided.
These and other objects of the present invention will become more apparent to those skilled in the art as the description thereof proceeds.